Jan. 12, 2011
Steve Cole
Headquarters, Washington
202-358-0918
stephen.e.cole@nasa.gov
Leslie McCarthy
Goddard Institute for Space Studies, New York
212-678-5507
leslie.m.mccarthy@nasa.gov
RELEASE: 11-014
NASA RESEARCH FINDS 2010 TIED FOR WARMEST YEAR ON RECORD
WASHINGTON -- Global surface temperatures in 2010 tied 2005 as the
warmest on record, according to an analysis released Wednesday by
researchers at NASA's Goddard Institute for Space Studies (GISS) in
New York.
The two years differed by less than 0.018 degrees Fahrenheit. The
difference is smaller than the uncertainty in comparing the
temperatures of recent years, putting them into a statistical tie. In
the new analysis, the next warmest years are 1998, 2002, 2003, 2006,
2007 and 2009, which are statistically tied for third warmest year.
The GISS records begin in 1880.
The analysis found 2010 approximately 1.34 F warmer than the average
global surface temperature from 1951 to 1980. To measure climate
change, scientists look at long-term trends. The temperature trend,
including data from 2010, shows the climate has warmed by
approximately 0.36 F per decade since the late 1970s.
"If the warming trend continues, as is expected, if greenhouse gases
continue to increase, the 2010 record will not stand for long," said
James Hansen, the director of GISS.
The analysis produced at GISS is compiled from weather data from more
than 1000 meteorological stations around the world, satellite
observations of sea surface temperature and Antarctic research
station measurements. A computer program uses the data to calculate
temperature anomalies -- the difference between surface temperature
in a given month and the average temperature for the same period
during 1951 to 1980. This three-decade period acts as a baseline for
the analysis.
The resulting temperature record closely matches others independently
produced by the Met Office Hadley Centre in the United Kingdom and
the National Oceanic and Atmospheric Administration's National
Climatic Data Center.
The record temperature in 2010 is particularly noteworthy, because the
last half of the year was marked by a transition to strong La Nina
conditions, which bring cool sea surface temperatures to the eastern
tropical Pacific Ocean.
"Global temperature is rising as fast in the past decade as in the
prior two decades, despite year-to-year fluctuations associated with
the El Nino-La Nina cycle of tropical ocean temperature," Hansen and
colleagues reported in the Dec. 14, 2010, issue of Reviews of
Geophysics.
A chilly spell also struck this winter across northern Europe. The
event may have been influenced by the decline of Arctic sea ice and
could be linked to warming temperatures at more northern latitudes.
Arctic sea ice acts like a blanket, insulating the atmosphere from the
ocean's heat. Take away that blanket, and the heat can escape into
the atmosphere, increasing local surface temperatures. Regions in
northeast Canada were more than 18 degrees warmer than normal in
December.
The loss of sea ice may also be driving Arctic air into the middle
latitudes. Winter weather patterns are notoriously chaotic, and the
GISS analysis finds seven of the last 10 European winters warmer than
the average from 1951 to 1980. The unusual cold in the past two
winters has caused scientists to begin to speculate about a potential
connection to sea ice changes.
"One possibility is that the heat source due to open water in Hudson
Bay affected Arctic wind patterns, with a seesaw pattern that has
Arctic air downstream pouring into Europe," Hansen said.
For more information about GISS's surface temperature record, visit:
http://data.giss.nasa.gov/gistemp/
For more information about NASA and agency programs, visit:
http://www.nasa.gov
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